CLONING OF THE HISTIDINE BIOSYNTHETIC GENES OF CORYNEBACTERIUM-GLUTAMICUM - ORGANIZATION AND SEQUENCING ANALYSIS OF THE HISA, IMPA, AND HISF GENE-CLUSTER

The hisA and hisF genes of Corynebacterium glutamicum were cloned by t ransforming histidine auxotrophic Escherichia coli with the genomic DN A library. They are two of the eight genes that participate in the his tidine biosynthetic pathway. Cloned DNA fragments containing the genes can also complement hisH and hisI auxotrophs of Escherichia coli, sug gesting that the four genes are clustered in the genome. We determined the nucleotide sequences of the minimal fragment containing the hisA and hisF genes, which are separated by the impA gene. The coding regio ns of the hisA and hisF genes are 245 and 257 amino acids in length wi th a predicted size of about 26 and 27 kDa, respectively. These are in good agreement with the sizes of proteins expressed in E. coli. A hig h similarity was observed in comparison of nucleotide sequences of eac h protein between C. glutamicum and other species, as well as those be tween hisA and hisF genes of C.glutamicum. (C) 1998 Academic Press.